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LONDON, United Kingdom — Ruthless on immigration, cracking down on civil rights and apparently keener on airstrikes than John McCain, there’s a hawkish new player on the political scene and she’s wearing kitten heels.

Theresa May, Britain’s Home Secretary, led the government’s cheerleading of missile attacks on ISIS this week from the annual convention of the Conservative Party. Soon she hopes to be leading the entire country.

From the party conference stage on Wednesday, May was described in words that cannot be bettered in Conservative Party folklore: “The Iron Lady.”

She is the first serious contender to emulate Margaret Thatcher and become Britain’s second woman Prime Minister. She may even become leader of the Conservatives before Hillary Clinton’s shot at the White House in 2016 if David Cameron loses the election next year.

In her convention speech, May addressed the threat of ISIS creating the “world’s first truly terrorist state” with a look of steely determination. “We must not flinch,” she said. “We must act to destroy them.”

Party activists rejoiced in the red meat being thrown from the stage, and she had more; extreme Islamic preachers at home should be targeted even if they didn’t break the law. They should be prevented from spreading their message on social media and banned from television. One of those preachers admitted to The Daily Beast that he was taken aback by her zeal.

As Home Secretary, May is in charge of Britain’s law enforcement, national security and border control. With so many areas for potential strife, none of the past five Home Secretaries lasted more than two years in the job. May, by contrast, looks stronger with every passing month. “She has staged a revolution,” said one former security advisor.

Uncompromising and efficient policymaking is not May’s only strength; she is an impressively nuanced politician. The tirade against Islamists at home and abroad was preceded by a moving call for an end to stop-and-search profiling, which she argued had humiliated and alienated generations of black men. This, the audience did not expect, or want, to hear.

May has a reputation for stylishly delivering unpalatable truths. More than a decade earlier she strode on stage before the same convention audience in a pair of leopard print heels that would make almost as many headlines as the stunning speech she was about to give.

This was at the height of Tony Blair’s Labour government, and she looked her Conservative colleagues in the eye and told them they needed to change fundamentally everything they were doing, their opponents were right— they had become “the nasty party.”

“Twice we went to the country unchanged, unrepentant, just plain unattractive. Twice we got slaughtered,” she told the elderly, right-wing audience.

There are a few in the party who have never forgiven her for that sound bite, which captured public opinion and resonated far beyond the conference hall. But her moment of self-reflection helped to set the tone for the following decade in which the party softened its image and eventually made it back to power with the moderate figure of David Cameron at the helm.

Ironically, while Cameron’s position in the party is in jeopardy because of his moderate positions, May has been winning over right-wingers with her powerful grip on the Home Office. If the Conservatives lose next year, a new leader will almost certainly be required and contenders are thin on the ground, or rather lightweight. The bookies’ favorite is Boris Johnson, the ebullient Mayor of London, but his standing in the betting may more accurately reflect his popularity with the public than his chance of becoming leader, since he is loathed by a section of Tory MPs who dislike his attention-seeking buffoonery—and it is the MPs who vote for the leader of their party (and thus, by extension, the PM).

The charmless George Osborne is David Cameron’s second-in-command and probably his preferred heir, but the party seems unlikely to go for a similar-looking man with a near-identical privileged upbringing.

May, by contrast, is the daughter of a clergyman (like Angela Merkel to whom she is often compared, not least because she can seem a bit humorless) and was educated at an ordinary school, from where she made her own way to Oxford University.

She is known to be incredibly hard working, and is widely respected by her fellow party members, who see her as steely and determined and yet, crucially, seems just human enough to connect with the public (the bookies rate her second favorite for next leader after Johnson at 4/1).

May considers Twitter a waste of time, and has only ever given one “personal” interview, to the Daily Telegraph in 2012 in which she spoke of her sadness at not having children.

“You look at families all the time and you see there is something there that you don’t have,” she said.

But that appears to have been enough humanizing for Theresa May. Apart from the outfits, of course, some of which have been quite outlandish. Catherine Meyer, wife of the former British ambassador to the United States, who is a friend of May’s, told the Financial Times earlier this year that May is a “serious woman” but also, “talks about holidays, clothes. She’s quite girly in that sense.”

May has clearly made a decision not to take offense at coverage of her clothing choices. Last year she was photographed wearing knee-high boots and then, a few days later, a £1,190 ($1,900) Vivienne Westwood tartan suit, leading the Daily Mail to ask whether the Home Secretary was “the new Cara Delevingne,” who had worn the same outfit a few months earlier.

Instead of taking offense, and calling the media on their undoubted sexism, May played a smarter game; speaking as she collected the Spectator’s Politician of the Year award last month, the 57-year-old said: “This is the second good thing that’s happened to me today , because this morning, the Daily Mail asked: ‘Is Theresa May the new Cara Delevingne?’ For those of you who don’t know, she is 21, a supermodel and one of the most beautiful women in the world—so I think we can safely say that the answer to that is no.”